Gas samples are typically wet, hot and dirty, while analysers need samples to be dry, cool and clean.  The new GASS™-II Gas Analysis Sampling System from Perma Pure® is designed to prepare demanding gas samples for analysis.    Intended particularly to remove acid mists that can damage analysers, it also continuously removes other coalescable liquids, water and particulates without altering the concentrations of typical analyte gases such as CO, CO2, HCl, NOX, O2 and SO2.

The GASS-II system includes a separately heated coalescing filter with automatic drain to remove acid mists before drying.  This makes its use appropriate when, for example, fuels containing high sulphur levels are burned, resulting in high levels of sulphuric acid.  It accepts samples containing as much as 75% water at rates of up to 25 litres per minute.  Particulates as small as 1 micrometre are removed, and water content is reduced to a dew point as low as -35°C, while oxides of carbon, nitrogen, and sulphur are quantitatively retained within the sample.

Unlike chiller/condensers, the system selectively removes water directly from the vapour phase using patented Nafion® membrane dryers.  Consequently, water-soluble analyte gases are not lost through dissolution in condensate, and the water content of the sample is reduced to a much lower dew point.  Drying is a continuous, self-regenerating process and no routine maintenance is required. 

The unit is protected with safety interlocks and alarms.  It is insulated and environmentally sealed so it can be stack-mounted to dry the sample at the source, eliminating costly, heated sample lines.  By drastically reducing the water content of sample gases, the system also shortens the equilibration time during the change from wet sample to dry calibration gases, cutting consumption of costly gas standards.

Other models of the GASS family of products offer lower cost alternatives for less demanding applications.  GASS-II sampling systems and Nafion dryers are manufactured exclusively by Perma Pure® LLC, a member of the Halma Group.  For more information visit the website at www.permapure.com, or e-mail info@permapure.com.

Nafion is a registered trademark of DuPont